Expand description
Unix timestamp -> formatted string conversion.
unix_to_parts decomposes a Unix timestamp into (year, month, day, hour, minute, second)
using the Gregorian calendar algorithm (proleptic calendar, UTC only, no DST).
apply_pattern performs simple string substitution on strftime-like tokens:
%Y (4-digit year), %m (month), %d (day), %H (hour), %M (minute), %S (second).